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Epic exoplanet 61 EP

HD 217107 b

RA 344.5647° · Dec -2.3954° · exoplanet

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Score breakdown

· 7 badges
61 pts · Epic
Epic 78 pts → Anomaly
  • Found before the year 2000 +18
  • Hot Jupiter +10
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 61

17 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Hot Jupiter · +10
  • Tidally locked · +10
  • Multi-planet system · +6
  • Orbits a Sun-like star · +8
  • Found before the year 2000 · +18

Trivia

What it actually is

  • Hugging its star. It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.
  • What it is made of. Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.
  • Crowded system. One of at least 2 planets orbiting its star.

Sense of scale

  • In perspective. Inside our stellar backyard: every radio broadcast humanity has ever made has already swept past it.

Find it in the sky

  • How to spot it. At magnitude 6.2 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around September — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Properties

density gcc
1
diameter km
173484.32
discovery facility
Lick Observatory
discovery method
Radial Velocity
discovery year
1998
dist ly
65.4331
eccentricity
0.1284
eq temp k
1105.84
host star teff
5622
inclination
93
insolation
231.1546
mag
6.155
mass earth
459.5799
name
HD 217107 b
orbital period days
7.127
radius earth
13.6
semi major au
0.0736
spect
G
sys num planets
2
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About HD 217107 b

HD 217107 b is an epic exoplanet. It lies about 65.4 light-years from Earth, shines at apparent magnitude 6.16, has spectral type G and has an equilibrium temperature near 1,106 K.

It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.

How to see it

At apparent magnitude 6.16, it is an easy target for binoculars.

Like any astronomical target, HD 217107 b is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why HD 217107 b is an epic exoplanet

HD 217107 b scores 61 points on Spacedle's rarity scale, which places it in the epic tier. Another 17 points would lift it into a rarer tier.

That score comes from 7 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter, Tidally locked, Multi-planet system, Orbits a Sun-like star and Found before the year 2000 — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.